Combustion grate particularly designed for burning refuse such as garbage



Dec. 31, 1968 R. HOLSTEIN ETAL 3, ,9

COMBUSTION GRATE PARTICULARLY DESIGNED FOR BURNING REFUSE SUCH AS GARBAGE Filed March 16, 1967 INVENTORS RIC HA PD HOLS TE/N HERBERT VO/G 7' A T TORNE Y5 United States Patent C 3,418,998 COMBUSTION GRATE PARTICULARLY DESIGNED FOR BURNING REFUSE SUCH AS GARBAGE Richard Holstein, Denkendorf, and Herbert Voigt, Esslingen, Germany, assignors to Haniel & Lueg G.m.b.H., Dusseldorf-Grafenberg, Germany Filed Mar. 16, 1967, Ser. No. 623,741 Claims priority, applicatitsin glesrmany, Mar. 16, 1966,

1 5 Claims. (Cl. 126176) ABSTRACT OF THE DISCLQSURE A combustion grate, particularly designed for burning refuse, including garbage, includes relatively oscillatable grate sections arranged in series in the direction of fuel conveyance and each having a circular sector profile converging to a narrow restricting edge. The axis of oscillation of each section is coincident with the narrow restricting edge and forms the axis of cylindrical trunnions or the like oscillatably supporting the section. This axis, and the narrow constricting edge, are contiguous with the succeeding grate section so that there is no relative movement between each grate section, at its narrow restricting edge, and the surface of the suceeding grate section.

Background of the invention The invention is directed to combustion grates for burning refuse such as garbage and, more particularly, to a novel multi-section combustion grate for this purpose, including oscillatable grate sections arranged serially in the direction of fuel conveyance, and in which jamming of the oscillatory movement of the grate sections is essentially prevented. In the burning of refuse including garbage, which usually are inferior and ballast-containing fuels, it is essential not only that the fuel layer be moved but also that it be loosened up. Consequently, combustion grates for garbage burning plants have been designed to include indivdual grate sections arranged in series in the direction of fuel conveyance. Each of these grate sections has, in side elevation, a circular sector profile and is oscillatable upwardly and downwardly about an axis of oscillation extending transversely of the direction of fuel conveyance.

Experience has indicated that difiiculties may be encountered, in known refuse burning plants, due to incombustible and relatively non-crushable components of the fuel. These components include, for example, screws, bolts, nails, steel balls, sparkplugs, etc. The components become stuck between the individual grate sections, and this has the disadvantageous eifect of hindering or jamming oscillation of the grate sections.

Summary of the invention In accordance with the invention, an improved combustion grate for burning refuse, garbage and the like is provided which is less susceptible to trouble due to incombustible and substantially non-crushable components in the fuel.

In accordance with the invention, the problem is solved by arranging the axis of oscillation of each circular sector profile grate section at that point of its profile outline which touches the corresponding following grate section. To the extent to which the distance between the axis of oscillation and the profile outline is reduced, when displacing the oscillation axis relative to the profile outline, there results a reduction of relative displacement of two adjacent grate sections. In effect, this amounts to a reduction in the radius ofoscillation and results in a reduction of a tendency of incombustible and substantially noncrushable components of the fuel to becoming stuck or jammed between adjacent grate sections.

Protection against sticking of these components of the fuel can also be insured if the circular arc of the circular sector profile of each grate section is arranged eccentrically to the axis of oscillation of the grate section. Generally, however, it is more advantageous to provide a circular are which is concentric with the axis of oscillation, so that the grate sections, throughout the entire swinging movements thereof, will remain in contact.

In cases where the refuse or garbage to be burned does not contain any industrial refuse, but comprises essentially only household garbage containing very little incombustible and essentially non-crushable components, the grate sections, in accordance with the invention, may be so arranged in series that the axis of oscillation of each grate section is in contact with a circular arc of the respective immediately succeeding grate section.

Accordingly, an object of the invention is to provide an improved combustion grate for burning refuse such as garbage.

Another object of the invention is to provide an improved combustion grate for burning refuse, such as garbage, comprising plural oscillatable grate sections arranged in series in the direction of fuel conveyance, and which is essentially not susceptible to jamming of the individual sections by non-combustible and substantially non-crushable components of the fuel.

A further object of the invention is to provide an improved combustion grate, particularly designed to burn refuse such as garbage, and which is a multi-section grate including grate sections arranged in series in the direction of fuel conveyance and each oscillatable about an axis of oscillation extending transversely of the direciton of fuel conveyance, and involving a displacement of the oscillation axis of each grate section relative to its circular sector profile outline.

Yet another object of the invention is to provide an improved combustion grate, of the type just mentioned, in which the circular arc of the circular sector profile of each grate section is concentric with the axis of oscillation of the grate section.

A further object of the invention is to provide an improved combustion grate of the type mentioned, in which the axis of oscillation of each grate section is in contact with or immediately adjacent the circular arc of the immediately succeeding grate section.

Brief description of the drawings Referring finst to FIGS. 1 and 2, the refuse burning grate partially illustrated therein includes oscillatable grate sections 1 alternating with relatively stationary bridging grate sections 2. In side elevation, each of the oscillatable grate sections 1 has a circular sector profile -converging to a narrow restricting edge, and is oscillatable about an axis of oscillation 3 which is the axis of cylindrical bearing members or trunnions rotatably arranged in a support structure 4, such as a wall of a combustion chamber. The several grate sections are arranged serially along the direction of fuel conveyance, with the movable sections 1 alternating with the bridging sections 2, and the axes of oscillation extending transversely of the direction of fuel conveyance.

As illustrated in FIG. 1, each axis of oscillation 3 of a section 1 is coincident with the narrow restricting edge of the associated section and lies against the combustion supporting surface of the succeeding bridging grate section 2. As indicated by arrow 5, grate sections 1 are swung upwardly and downwardly about axes 3 Without any movement of axes 3, or the narrow restricting edges of the sections, relative to the bridging sections 2. Consequently, the materialto be burned cannot become stuck or jammed between the axes of oscillation 3 and the bridging grate sections 2.

As illustrated in FIG. 1, each grate section 1 has a circular sector profile converging to a narrow restricting edge and including a circular are k which is concentric with the associated axis of oscillation 3. The outline of the oscillatable sections 1, as shown in FIG. 1, is only an example. Many modifications of the form of the outline are possible for adaptation of the grate to prevailing conditions with respect to combustion and operation.

As is particularly apparent from FIG. 2, the oscillatable grate sections 1 are assembled, in a known manner, from individual grate bars 1', which may be combined into groups or which may be replaced by sub-divided plates. Also, and with particular reference to FIG. 1, it will be noted that the fuel supporting surface of each section 1 includes a substantially horizontal portion followed by a portion sloping toward the next succeeding bridging grate section 2.

FIG. 3 shows a grate comprising only oscillatable grate sections 1. In this case, the axes 3, which are coincident with the narrow constricting edges, are positioned immediately adjacent, or in contact with, the circular are k of the next succeeding grate section considered in the direction of fuel conveyance. The side elevation profile of each grate section may be modified in a manner such that the fuel supporting surface thereof is not a rectilinearly aligned continuation of the radius of the circular are k of the immediately succeeding grate section. Thus, and as is particularly apparent in FIG. 3, there are horizontal combustion surfaces alternating with sloping combustion surfaces, each grate section 1 including such a horizontal combustion surface followed by a combustion surface sloping toward its narrow restricting edge, which is coincident with its oscillation axis 3, and discharging onto the horizontal combustion surface of the next succeeding grate section. Thus, during oscillation of a grate section, its grate surface will not form a cone or wedge of decreasing angle with the circular are surface of the next succeeding grate section. If this were the case, the material to be burned and carried by the then stationary grate section would be drawn into such a narrowing trough by the succeeding grate section during downwardly swinging movement.

The inclination of the grate depends on the operational requirements, which also determine the overall length of the grate as well as the length of the individual grate areas. Such details form no part of the invention and have no effect whatsoever upon the advantages resulting from the invention.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. In a refuse burning grate, particularly designed for garbage burning plants, having grate sections arranged successively in the direction of fuel conveyance and including movable grate sections, oscillatable on pivots at opposite sides of the grate, and which, in side elevation, have a circular sector profile including a circular arc and converging to a narrow restricting edge at the center of intersecting radii of the circular arc, the axes of oscillation of the sections extending transversely of the direction of fuel conveyance and being coaxial with the axes of symmetry of the respective pivots: the improvement in which the axis of oscillation of each movable grate section is coincident with the narrow restricted edge of the latter, which narrow restricted edge is contiguous with the next succeeding grate section.

2. A refuse burning grate, as claimed in claim 1, in which each movable grate section is immediately succeeded by a relatively stationary bridging grate section.

3. A refuse burning grate, as claimed in claim 1, in which the circular arc of the side elevation profile of each movable grate section is concentric with the axis of oscillation of the respective movable grate section.

4. A refuse burning grate, as claimed in claim 1, including only oscillatable grate sections; the axis of oscillation of each oscillatable grate section abutting the circular arc of the side elevation profile of the immediately suc ceeding oscillatable grate section.

5. A refuse burning grate, as claimed in claim 1, in which the combustion surface of each oscillatable grate section includes a surface portion which is normally horizontal in the stationary position of the associated grate section and succeeded by a sloping portion extending to the combustion surface of the next succeeding grate section.

References Cited UNITED STATES PATENTS 1,460,618 7/1923 Stimmel 1l0-39 1,586,963 6/1926 Budd l26-176 X 3,057,309 10/ 1962 Turner et al 126l76 X FOREIGN PATENTS 435,760 9/1935 Great Britain.

CHARLES J. MYHRE, Primary Examiner.

US. Cl. X.R. 1l039. 

